The present invention relates to the field of the art of connecting fittings in water supply networks in general and in particular to the field of connecting fittings suitable for flexible plastic conductors of water supply networks and hydraulic installations in general.
The broad circulation of flexible plastic conductors for hydraulic installations in water supply networks and in central heating and air-conditioning networks as well, has created the need for the development of new connecting fittings of the said conductors to the conventional commercially available water taps or radiator valves. The coating of the said plastic conductors with another spiral type covering conductor is necessary, so as to enable when required replacement of a portion of the plastic conductor which presents a malfunction with another new portion of plastic conductor, capable of passing through the same permanently installed spiral-type covering conductor. In this way repair or replacement of parts in the network becomes possible without costly repair work.
It was henceforth necessary to produce couplings, elbows, etc. by means of which one would be able to connect the conventional water supply, radiator valves, etc. to the shorter diameters of flexible plastic conductors.
In order to ensure the inspection and replacement of portions of the flexible plastic conductors which are contained within the spiral type covering conductors, it became necessary to mount the said couplings, elbows, etc. within an independent plastic housing, where this housing is built into the wall with a free end left for the connection to the metallic tap, valve, etc. The metallic couplings, elbows, etc. are sufficiently protected from corrosion, enclosed within the said plastic housing.
By way of example such a plastic housing has developed in order to house a metallic water supply elbow. The practical experience of such plastic housings of water supply elbows comprising a single, solid or a couple of pieces has presented certain disadvantages, relating to the facility of performing the necessary connections on the one hand to the flexible plastic conductor with the spiral covering and on the other hand to the metallic water tap or valve. The process of disconnecting, if necessary, is even more difficult. A disadvantage of the above plastic housings for water supply elbows of the prior art is that because of their construction in one single or two pieces allow only for the connection and usage with a certain maximum diameter of the spiral covering conductor and this necessitates the provision of plastic housings of different dimensions to cover for spiral coverings of different diameters. Furthermore if for a two-piece housing, one piece is pressed against the other in order to afford their connection, the cost of manufacturing is higher since such a connecting process involves materials with a desired increased elasticity and it further involves restricted manufacturing tolerances. Furthermore, such a fitting process of pressing one piece of the plastic housing against the other, results in the assembly and most particularly the dismantling of the housing becoming difficult because of the relatively high stresses developed, which are difficult to handle manually. Such a process does further result to noise.
Another disadvantage of such plastic housings for metallic water supply elbows of the prior art relates to the dimensions and in particular the internal length and diameter within which the water supply elbow moves and has to be pulled out when it is required to change a portion of the flexible conductor. As time goes by, the plastic conductor generally suffers from a hardening process leading to a respective loss of flexibility. The plastic conductor may furthermore develop serpentine fluctuations, resulting to further diffuculties in its smooth pulling out. It is for the above stated reasons that it is of special importance to facilitate movement of both the metallic water supply elbow and the plastic conductor by providing the maximum possible internal dimensions of length and diameter and by freeing the interior of the housing from ribs and other formations that may obstruct such movement.
An object of the present invention is to efficiently overcome the above disadvantages and drawbacks of the prior art, providing a water supply elbow within a plastic housing comprising three or more parts, which is thereby suitable for connection to plastic conductors with a plastic spiral covering of varying diameters, which is of very simple and economical construction, substantially facilitating the process of assembly and dismantling of all kinds of water supply elbows, subjectable to minimal operational stresses and thereby presenting a high strength and long service life.
Another object of the present invention is to provide the metallic water supply elbow with changeable fitting accessories to flexible plastic conductors, so that it may be easy to change defective fitting accessories as well as to use the same main body of the metallic water supply elbow with flexible plastic conductors of varying diameters.
These and other objects, characteristics and advantages of the proposed water supply elbow with a plastic housing comprising three or more parts, connectable to plastic conductors with a spiral covering of varying diameters will become apparent in the following analytical description of the invention.